Ion charge state fluctuations in vacuum arcs
Abstract
Ion charge state distributions of cathodic vacuum arcs have been investigated using a modified time-of-flight method. Experiments have been done in double gate and burst gate mode, allowing us to study both systematic and stochastic changes of ion charge state distributions with a time resolution down to 100 ns. In the double gate method, two ion charge spectra are recorded with a well-defined time between measurements. The elements Mg, Bi, and Cu were selected for tests, representing metals of very different properties. For all elements it was found that large stochastic changes occur even at the limit of resolution. This is in agreement with fast changing arc properties observed elsewhere. Correlation of results for short times between measurements was found but it is argued that this is due to velocity mixing rather than due to cathode processes. The burst mode of time-of-flight measurements revealed the systematic time evolution of ion charge states within a single arc discharge, as opposed to previous measurements that relied on data averaged over many pulses. The technique shows the decay of the mean ion charge state as well as the level of material-dependent fluctuations.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE. National Nuclear Security Administration, Initiativesof Proliferation Prevention Project IPP-LBNL-T2-196; Grant of thePresident of Russia MD-148.2203.02, Nippon Sheet Glass Co Ltd
- OSTI Identifier:
- 876720
- Report Number(s):
- LBNL-56737
R&D Project: Z2N196; BnR: NN4101010; TRN: US0601247
- DOE Contract Number:
- DE-AC02-05CH11231
- Resource Type:
- Journal Article
- Journal Name:
- Journal of Physics D: Applied Physics
- Additional Journal Information:
- Journal Volume: 38; Related Information: Journal Publication Date: 2005
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CATHODES; CHARGE STATES; DECAY; FLUCTUATIONS; RESOLUTION; SPECTRA; TIME RESOLUTION; TIME-OF-FLIGHT METHOD; VELOCITY; Cathodic arcs plasma fluctuations
Citation Formats
Anders, Andre, Fukuda, Kentaro, and Yushkov, Georgy Yu. Ion charge state fluctuations in vacuum arcs. United States: N. p., 2004.
Web.
Anders, Andre, Fukuda, Kentaro, & Yushkov, Georgy Yu. Ion charge state fluctuations in vacuum arcs. United States.
Anders, Andre, Fukuda, Kentaro, and Yushkov, Georgy Yu. 2004.
"Ion charge state fluctuations in vacuum arcs". United States. https://www.osti.gov/servlets/purl/876720.
@article{osti_876720,
title = {Ion charge state fluctuations in vacuum arcs},
author = {Anders, Andre and Fukuda, Kentaro and Yushkov, Georgy Yu},
abstractNote = {Ion charge state distributions of cathodic vacuum arcs have been investigated using a modified time-of-flight method. Experiments have been done in double gate and burst gate mode, allowing us to study both systematic and stochastic changes of ion charge state distributions with a time resolution down to 100 ns. In the double gate method, two ion charge spectra are recorded with a well-defined time between measurements. The elements Mg, Bi, and Cu were selected for tests, representing metals of very different properties. For all elements it was found that large stochastic changes occur even at the limit of resolution. This is in agreement with fast changing arc properties observed elsewhere. Correlation of results for short times between measurements was found but it is argued that this is due to velocity mixing rather than due to cathode processes. The burst mode of time-of-flight measurements revealed the systematic time evolution of ion charge states within a single arc discharge, as opposed to previous measurements that relied on data averaged over many pulses. The technique shows the decay of the mean ion charge state as well as the level of material-dependent fluctuations.},
doi = {},
url = {https://www.osti.gov/biblio/876720},
journal = {Journal of Physics D: Applied Physics},
number = ,
volume = 38,
place = {United States},
year = {Tue Dec 14 00:00:00 EST 2004},
month = {Tue Dec 14 00:00:00 EST 2004}
}